Rage Spawn (HELP)

I am creating a map for a server, and I set world spawn on a certain spot. When I do /kill to see if it spawns me on my spot, it spawns me in the water around my spawn. I need the spawn to be on 1 specific block for the map to be good. Is it possible to make it so it spawns on that one block?

Hope someone can answer my question.

Thanks,
TfortuneT